str1="hello word"
str2='hello word!'
str3='''hello word'''
print(str1)
print(str2)
print(str3)
print('hel\'lo word') #\转义符
print('123---{0}---{1}'.format(4,5))
str1='hello'
print(f'123---{str1}')

#显示进度
for i in range(0,101,2):
    print("=========开始下载========")
    if i==100:
        print("下载完成")
    else:
        print(f'{i}%','[',"*"*(i//2)," "*(100-i//2),']')